Textile bobbin

ABSTRACT

A textile bobbin for the winding of synthetic filament yarn is described, which bobbin comprises a cylindrical winding surface having a plurality of indentations superimposed upon the outer surface thereof in the form of parallel microgrooves, said grooves running the length of said surface substantially parallel to the axis of the cylindrical winding surface. The microgrooves provide a surface upon which filament yarn is more easily grasped initially in the beginning of a winding stage, and more particularly provides a substantially lower takeoff tension in the unwinding of the last layers of yarn from said bobbin surface.

United States Patent 19 [11] 3,746,275 Whisnant July 17, 1973 [54] TEXTILE BOBBIN [75] Inventor: John K. Whisnant, Shelby, N.C. Primary Examiner-George Mautz Attorney-Thomas J. Morgan, Herbert M. Adrian, Jr. [73] Assignee: Fiber Industries, Inc., Charlotte, d S D, M h

221 Filed: Apr. 9, 1971 [57] ABSTRACT A textile bobbin for the winding of synthetic filament [21] Appl' 132,845 yarn is described, which bobbin comprises a cylindrical winding surface having a plurality of indentations su- 52 us. (:1. 242/ll8.32 Perimposed upon the Outer Surface thereof in the form [51] Int. Cl.... B65h 75/10, B65h 75/26 of Parallel microgroovcs Said grooves running the 58 Field of Search 242/1 18.32, 118.3, length of Said Surface Substahhally Parallel to the axis 242 13 31 11 11 11 1 of the cylindrical winding surface. The microgrooves provide a surface upon which filament yarn is more 5 R f r Ci easily grasped initially in the beginning of a winding UNITED STATES PATENTS stage, and more particularly provides a substantially 3 544 034 12/1970 Jumey et al 18 32 lower takeoff tension in the unwinding of the last layers 3:095:16] 6/1963 Atwood ct a]. 242/11s.3 x of yam {mm and bobbm Surface 2,163,618 6/1939 Muller 242/1 18.3 5 Claims, 3 Drawing Figures PATENIED m w 1 FIG,I

TEXTILE BOBBIN BACKGROUND Numerous bobbin designs are known in the art for the winding of synthetic filament yarns. Such bobbins are used for many purposes and in many instances, the particular bobbin is designed for the particular subsequent use to which the yarn is intended.

In the manufacturing of synthetic filament yarn such as polyester and nylon continuous filaments, yarn is often times wound in the flat untextured state onto bobbins and shipped or passed thereon to a subsequent processing step which may be either a knitting step, beam warping step, texturing step or the like. Particularly when the subsequent step involves the texturing of the yarn such as by false twist texturing, gear crimping and the like well known processes, the yarn is unwound from the bobbin and fed directly to a texturing machine under certain specified tensioning conditions. Variations in the'tension of such yarn in the unwinding state can greatly affect the texturing, as is particularly exemplified in what is called lean ends. Lean ends are found to occur particularly during the take off of the last layers of yarn from bobbins of prior art design. The lean ends are believed to be caused by the increase in the yarn tension as the last layers of yarn are removed from the bobbin. The increase in tension reduces the degree of texturing imparted to the yarn in the texturing operation. Such decreased texturing shows up in the resulting yarn as a defect and is referred to as a lean end because of the lower level of texturing found in such sections of yarn.

It is the object of the present invention to provide a bobbin which greatly reduces the occurrence of lean ends in subsequent texturing operations. It is another object of this invention to provide a bobbin which reduces the take-off tension of yarn from said bobbin during the unwinding of the last layers of yarn which are in contact with the bobbin surface. Further objects and improvements of the present bobbin will become apparent to those skilled in the art from the description herein.

These and other objects will become apparent from a description of the invention which follows.

THE INVENTION In accordance with the present invention, a textile bobbin is provided for the winding of synthetic yarns comprising a cylindrical winding surface having thereon a plurality of parallel microgrooves, said grooves running the length of said surface substantially parallel to the axes of the cylindrical winding surface,

said microgrooves being displaced from each other in the range of about 0.005 to 0.150 inch and said microgrooves having a depth in the range of about 0.0001 to 0.01 inch.

This bobbin, although of relatively simple design, overcomes a very serious problem which occurs in attempting to produce uniform textured filaments. The noted surface greatly reduces take-off tension of the yarn from the bobbin surface thereby reducing or substantially eliminating lean ends in textured products made from yarns taken off of such bobbin.

DETAILS OF THE INVENTION The invention is more clearly described by reference to the drawing in which FIG. 1 illustrates a cylindrical bobbin having microgrooves thereon running parallel to the axes of the cylindrical surface;

FIG. 2 is a sectional view along line 22 illustrating the cross-section of the bobbin; and

FIG. 3 is an enlargement ofa small section of the surface of the bobbin of FIG. 1 more clearly illustrating the microgrooves thereon.

Referring to the figures, the bobbin is of cylindrical structure which may be extruded plastic, sheet steel, hardened paper or other material possessing the required compressive strength to prevent collapsing of the bobbin under the retractive forces of the yarn wound thereon. The surface of the bobbin is grooved with microgrooves distributed substantially uniformly across the bobbin surface. The grooves are preferably closely spaced in parallel arrangement so as to reduce the surface area upon which the yarn makes contact with the bobbin when wound on the bobbin.

The microgrooves are preferably displaced from each other in a range of about 0.005 to 0.150 inch and more preferably from 0.01 to 0.10 inch apart. It is to be recognized, of course, that the particular distance apart can be varied depending upon the actual width of the groove itself. The groove width is preferably in the range of about 0.005 to 0.10, which width is preferably within the wide limits of the noted range, particularly within the range of 0.05 to 0.10 inch in width. The depth of said microgroove is in the range of about 0.0001 to about 0.01 inch. This depth is not critical because the yarn does not enter the groove, but merely passes across the top of said groove. Therefore, of a more critical nature is the width of the groove and the spacings between grooves. Such width and spacing determine the resulting frictional forces exerted against the yarn by the bobbin surface during the yarn take off.

The precise width and spacing of the grooves can be varied with the particular yarn being wound thereon and particularly the yarn characteristics, such as denier per filament, synthetic filament polymer and yarn finish. In essence, the most preferred embodiment utilizes a groove width to grooved spacing relationship in the range of 30 to percent grooved area on the surface 'of said bobbin and is more preferably in the range of 35 to 60 percent.

The cross section of the lands between grooves can be flat or angular with the particular choice depending on a number of factors, particularly the amount of surface area on the bobbin which is to come in contact with the yarn, the initial yarn gripping factor desired during yarn winding, the subsequent yarn take-off angle and the like. More angular lands result in better initial yarn gripping and since the subsequent yarn take-off angle is normally from one end of the bobbin whereas winding is substantially perpendicular to the bobbin axes, the initial winding friction is very much different from the window gripping action. Angular lands have the further advantage of reducing surface area with the same number of grooves, and therefor less grooves per inch can be used. However, the angle of the land cannot be too acute, less the yarn be damaged by the cutting action which could occur from a sharp edge of land point. Thus, with an angular land, the apex thereof can be rounded to reduce the possibility of yarn damage. Therefore, the angle of slope on the sidewalls of the grooves forming the lands can vary from about 30 to and more preferably about 60 to 90.

While the noted bobbin is most desirably utilized for the winding of synthetic continuous filaments such as polyester filaments such as polyethylene terephthalate; polyamide filaments such as polycaprolactam, polyhexamethylene adipamide and the like; cellulose acetate, rayon, acrylic, Darvan, Spandex and the like; stapled yarns can also be wound thereon, but the particularly described benefits derived therefrom are not as pronounced.

The denier of the filaments wound on such bobbins are normally in the textile range of 0.5 to about denier per filament, while carpet yarn and industrial filaments wound thereon have a denier per filament range of about 8 up to 30 or more. Total deniers of yarns which are readily handled on such bobbins are normally in the range of about to 500 for textile purposes and about 500 to 6,000 or more for carpet yarn purposes.

What is claimed is:

l. A bobbin for the winding of synthetic filament yarns comprising a cylindrical winding surface having thereon a plurality of parallel continuous and independent microgrooves, said grooves running the length of said surface substantially parallel to the axis of the cylindricai winding surface, said microgrooves being displaced from each other in the range of about 0.005 to 0.150 inch and said groove depth being in the range of about 0.0001 to 0.01 inch.

2. The bobbin of claim 1 wherein the cylindrical winding surface is constructed of plastic.

3. The bobbin of claim 1 wherein the groove width is in the range of about 0.005 to 0.10 inch.

4. The bobbin of claim 1 wherein the grooved area on the surface of said bobbin comprises 30 to percent recessed area.

5. In the texturing of filament yarns comprising the steps of supplying said yarns in the form of a package in layers on a bobbin, unwinding said layers including the last layers and passing said yarns to a texturizing zone, and thereafter collecting said yarns in the textured state, the improvement which comprises reducing the takeoff tension in said unwinding of said last layers of yarn which are in contact with said bobbins surface by providing a bobbin composed of a cylindrical base having a surface characterized by superimposed microgrooves running the length of said surface and generally parallel to the axis of said base. 

1. A bobbin for the winding of synthetic filament yarns comprising a cylindrical winding surface having thereon a plurality of parallel continuous and independent microgrooves, said grooves running the length of said surface substantially parallel to the axis of the cylindrical winding surface, said microgrooves being displaced from each other in the range of about 0.005 to 0.150 inch and said groove depth being in the range of about 0.0001 to 0.01 inch.
 2. The bobbin of claim 1 wherein the cylindrical winding surface is constructed of plastic.
 3. The bobbin of claim 1 wherein the groove width is in the range of about 0.005 to 0.10 inch.
 4. The bobbin of claim 1 wherein the grooved area on the surface of said bobbin comprises 30 to 80 percent recessed area.
 5. In the texturing of filament yarns comprising the steps of supplying said yarns in the form of a package in layers on a bobbin, unwinding said layers including the last layers and passing said yarns to a texturizing zone, and thereafter collecting said yarns in the textured state, the improvement which comprises reducing the takeoff tension in said unwinding of said last layers of yarn which are in contact with said bobbin''s surface by providing a bobbin composed of a cylindrical base having a surface characterized by superimposed microgrooves running the length of said surface and generally parallel to the axis of said base. 